Lack of HDR Standards Threatens 4K Market

Ultra HD TV has a problem. Even as UHD/4K TVs are being sold and companies like Netflix, YouTube and DirecTV are pushing 4K content, the standards required for getting the best 4K viewing experience still need work. A lot of work, according to
a recent report from SMPTE.

The ugly truth about Ultra HD is that the increase in resolution isn't worth it. Under most viewing circumstances, the human eye simply cannot perceive the difference. There is a step improvement in Ultra HD video, however, but it derives from other properties: high dynamic range (HDR) and wide color gamut (WCG).

The standards for HDR and WCG are still lacking. It's an issue that most TV technologists have known for months, if not years, but there's no telling how big a problem it might turn out to be. After all, when consumers found out their first "HD" TVs were only 720-lines instead of 1040, most of them just shrugged. Furthermore, millions of people bought HD TVs, watched only SD video on them, and didn't notice the lack of improvement.

But that's no guarantee that plunging into the 4K era despite a lack of HDR and WCG standards won't come back to bite the TV industry in the ass.

Yet forging ahead with 4K -- and 4K with non-standard HDR -- while lacking HDR/WCG standards increases the likelihood that more early adopters are going to be left with products that could become obsolete long before they should be.

And as more supposed HDR products start coming off production lines, how do you market them? "This is better 4K than the 4K we sold you last month. Remember what we told you about higher resolution being better? Well, actually there's this thing called 'wide color gamut' and -- what's a 'gamut'? OK, so..."

Complicating the situation, you can build displays with HDR/WCG that aren't 4K (or 8K -- the industry is already thinking that far ahead).

The parameters that make up HDR include higher peak luminance, lower minimum luminance, greater contrast range and improved precision, minimizing quantization errors that are beyond the capabilities of existing standards to deliver, the Society of Motion Picture and Television Engineers (SMPTE) report explains.

SMPTE says the lack of standards affects the entire TV ecosystem, ranging from content creation to editing/production, delivery and playback.

Displays: Modern displays are capable of tremendously greater luminance than ever, but being brighter isn't enough; blacks need to be blacker.

Capture: Image capture isn't so much a problem as is a lack of standards in how the captured content is encoded.

Production: There are various approaches proposed to create, transport, distribute and display HDR/WCG content. "This is an implementation challenge for broadcast workflows, which are complex in nature, highly automated and expensive to build," SMPTE notes. The recommendation is to standardize interface and metadata solutions. Also, should high frame-rate video become more common, problems might crop up with interfaces.

Playback: According to the organization's recent report, "The HDR Ecosystem needs imaging performance requirements that must be met with sufficient precision to ensure that high-quality color reproduction can be achieved on displays with different capabilities without introducing unacceptable artifacts. Properly designed HDR systems will dramatically improve the available creative palette and directly enhance the consumer experience."

A further complication: Some TV technologists are more concerned than others about extending the benefits of HDR (and WCG) to legacy displays.

Other issues range from production studio techniques to audio fidelity to ad insertion methods.

The MPEG committee is also evaluating the impact of HDR and whether it requires the addition or modification of various tools in the HEVC compression standard.

Internet streaming delivery of HDR content will also be defined by both future industry standards and proprietary delivery systems.

ARIB in Japan has published a standard for OETF (ARIB STD-­B67). NHK has announced its timetable for delivery to the home of HDRWCG images. DVB in Europe is actively looking at the available options for home delivery. ITU-­R SG-­6 on Broadcasting has a Rapporteur Group (RG24) Recommendations on HDR television systems. The Blu-­ray disc Association has produced a set of HDR specifications.

Of course, if HDR/WCG is to be marketed as something separate, somebody is going to have to come up with a catchier name. Vibracolor. Whoopie-Scope. Something. Anything.